Abstract:
The Abrolhos Bank, in Southern Bahia, Brazil, consists of a 200 km-wide expansion of the continental platform, covering about 46,000 square kilometers. There are extensive mangroves, seagrass and algae bottoms, submerged and emergent coral reefs, and a group of small volcanic islands that comprises the Abrolhos Archipelago. The region’s coral reef biodiversity is the highest registered in the ... Southern Atlantic, harboring large populations of razilian endemic coral and reef fish species. Abrolhos is characterized by a relict coral fauna that appears to have a relatively higher tolerance to muddy conditions than that of other regions. The Marine RAP survey team assessed 45 sites over an 18-day period (11–28 February 2000), including 19 expert specialists from Brazilian universities, NGOs and the Brazilian Government.

At each site, an underwater inventory was made of six faunal groups selected to serve as indicators of overall biodiversity. The faunel groups included corals, fishes, algae, polychaete worms, molluscs, and crustaceans (the last three groups were analyzed only on bottom-sediment samples). In addition to the species inventory, bottom-sediment samples were taken in the immediate vicinity of the reefs. Observations and data on reef fisheries were also gathered by a fisheries scientist who evaluated the abundance and size of the main target species at each site. Additionally, the knowledge about species occurrences from other papers, were compiled by specialists producing a more complete list of species for the region.

Nearly 1300 species were registered for the six biological groups surveyed, with the following distribution: 39 anthozoans of 21 families; 266 fishes of 79 families; 100 algae of 31 families; 90 polychaete worms of 37 families; 293 molluscs of 80 families; and 535 crustaceans of 116 families. Three algae, 17 mollusc and 11 crustacean species were registered for the first time in Brazil. Fifteen algae, 2 coral, 86 polychaete, 23 crustacean, and near 100 fish species were registered for the first time in the Abrolhos Bank. At least 17 mollusc and one fish species were new to science and are being descripted. Other groups such as some polychaete worms and crustacean (Ostracoda, Stomatopoda, Tanaidacea, Cumacea, Isopoda and Asellota) have also potentially new species but the absence of taxonomists for them did not allow an accurate estimation.

Data gathered on abundance and size of reef fishes indicates that the implemented portion of the park shows positive signs of protection, at least for some families. Sand and mud are the most common bottom sediments surrounding the reefs surveyed in the Abrolhos region. Coarse (gravel) sediments are relatively uncommon. High levels of siliciclastic-dominated sediments were not evident in most samples gathered during the RAP survey, probably because bottom samples were collected close to reefs and therefore contained bioclastic material from reef organisms, rather than sediment transported from shore. Muddy sediments were mostly of biogenic origin, probably resulting from bioerosional activities of various boring organisms. The major concerns for the long-term maintenance of the mosaic of marine and coastal ecosystems of the Abrolhos Bank are the insufficient representation of key biodiverse areas, lack of implementation and compliance to the laws or regulations of the currently existing MPA network, overall inefficient fisheries management and the large industrial projects related to the cellulose and oil industries.

The following fifteen recommendations are made to deal with these threats. 1) Expand the representation of key biodiverse areas into the existing network of marine protected areas of the Abrolhos; 2) Implement the largest marine protected area of the Abrolhos Bank, the Ponta da Baleia/Abrolhos Environmental Protected Area; 3) Enforce the fully protected areas of the Abrolhos Bank; 4) Improve existing partnerships with governmental and non-governmental organizations in order to integrate marine and coastal resources management; 5) Develop financial mechanisms to support coastal and marine conservation; 6) Enforce existing laws and enact more effective laws to regulate fishing activities; 7) Identify major sources of sediments that reach coral reefs and determine the extent (and scale) that sedimentation is affecting coral growth and recruitment; 8) Conduct additional biological surveys in other areas of the Abrolhos Bank; 9) Implement additional conservation programs for endangered marine life; 10) Expand and integrate current environmental monitoring programs; 11) Implement a national environmental awareness campaign focusing on marine ecosystems; 12) Strengthen community participation in conservation planning and management; 13) Regulate the oil and gas exploration, and mining; 14) Establish best-practices policies for companies operating in the region; 15) Regulate tourism/whale watching.

These activities will be the main focus of CI and partners in the following years.